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1/**************************************************************************
2 *
3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27/*
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29 */
30
31#define pr_fmt(fmt) "[TTM] " fmt
32
33#include <ttm/ttm_module.h>
34#include <ttm/ttm_bo_driver.h>
35#include <ttm/ttm_placement.h>
36#include <drm/drm_vma_manager.h>
37#include <linux/mm.h>
38#include <linux/pfn_t.h>
39#include <linux/rbtree.h>
40#include <linux/module.h>
41#include <linux/uaccess.h>
42
43#define TTM_BO_VM_NUM_PREFAULT 16
44
45static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
46 struct vm_area_struct *vma,
47 struct vm_fault *vmf)
48{
49 int ret = 0;
50
51 if (likely(!test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)))
52 goto out_unlock;
53
54 /*
55 * Quick non-stalling check for idle.
56 */
57 ret = ttm_bo_wait(bo, false, false, true);
58 if (likely(ret == 0))
59 goto out_unlock;
60
61 /*
62 * If possible, avoid waiting for GPU with mmap_sem
63 * held.
64 */
65 if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
66 ret = VM_FAULT_RETRY;
67 if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
68 goto out_unlock;
69
70 up_read(&vma->vm_mm->mmap_sem);
71 (void) ttm_bo_wait(bo, false, true, false);
72 goto out_unlock;
73 }
74
75 /*
76 * Ordinary wait.
77 */
78 ret = ttm_bo_wait(bo, false, true, false);
79 if (unlikely(ret != 0))
80 ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
81 VM_FAULT_NOPAGE;
82
83out_unlock:
84 return ret;
85}
86
87static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
88{
89 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
90 vma->vm_private_data;
91 struct ttm_bo_device *bdev = bo->bdev;
92 unsigned long page_offset;
93 unsigned long page_last;
94 unsigned long pfn;
95 struct ttm_tt *ttm = NULL;
96 struct page *page;
97 int ret;
98 int i;
99 unsigned long address = (unsigned long)vmf->virtual_address;
100 int retval = VM_FAULT_NOPAGE;
101 struct ttm_mem_type_manager *man =
102 &bdev->man[bo->mem.mem_type];
103 struct vm_area_struct cvma;
104
105 /*
106 * Work around locking order reversal in fault / nopfn
107 * between mmap_sem and bo_reserve: Perform a trylock operation
108 * for reserve, and if it fails, retry the fault after waiting
109 * for the buffer to become unreserved.
110 */
111 ret = ttm_bo_reserve(bo, true, true, false, NULL);
112 if (unlikely(ret != 0)) {
113 if (ret != -EBUSY)
114 return VM_FAULT_NOPAGE;
115
116 if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
117 if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
118 up_read(&vma->vm_mm->mmap_sem);
119 (void) ttm_bo_wait_unreserved(bo);
120 }
121
122 return VM_FAULT_RETRY;
123 }
124
125 /*
126 * If we'd want to change locking order to
127 * mmap_sem -> bo::reserve, we'd use a blocking reserve here
128 * instead of retrying the fault...
129 */
130 return VM_FAULT_NOPAGE;
131 }
132
133 /*
134 * Refuse to fault imported pages. This should be handled
135 * (if at all) by redirecting mmap to the exporter.
136 */
137 if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) {
138 retval = VM_FAULT_SIGBUS;
139 goto out_unlock;
140 }
141
142 if (bdev->driver->fault_reserve_notify) {
143 ret = bdev->driver->fault_reserve_notify(bo);
144 switch (ret) {
145 case 0:
146 break;
147 case -EBUSY:
148 case -ERESTARTSYS:
149 retval = VM_FAULT_NOPAGE;
150 goto out_unlock;
151 default:
152 retval = VM_FAULT_SIGBUS;
153 goto out_unlock;
154 }
155 }
156
157 /*
158 * Wait for buffer data in transit, due to a pipelined
159 * move.
160 */
161 ret = ttm_bo_vm_fault_idle(bo, vma, vmf);
162 if (unlikely(ret != 0)) {
163 retval = ret;
164 goto out_unlock;
165 }
166
167 ret = ttm_mem_io_lock(man, true);
168 if (unlikely(ret != 0)) {
169 retval = VM_FAULT_NOPAGE;
170 goto out_unlock;
171 }
172 ret = ttm_mem_io_reserve_vm(bo);
173 if (unlikely(ret != 0)) {
174 retval = VM_FAULT_SIGBUS;
175 goto out_io_unlock;
176 }
177
178 page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
179 vma->vm_pgoff - drm_vma_node_start(&bo->vma_node);
180 page_last = vma_pages(vma) + vma->vm_pgoff -
181 drm_vma_node_start(&bo->vma_node);
182
183 if (unlikely(page_offset >= bo->num_pages)) {
184 retval = VM_FAULT_SIGBUS;
185 goto out_io_unlock;
186 }
187
188 /*
189 * Make a local vma copy to modify the page_prot member
190 * and vm_flags if necessary. The vma parameter is protected
191 * by mmap_sem in write mode.
192 */
193 cvma = *vma;
194 cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);
195
196 if (bo->mem.bus.is_iomem) {
197 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
198 cvma.vm_page_prot);
199 } else {
200 ttm = bo->ttm;
201 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
202 cvma.vm_page_prot);
203
204 /* Allocate all page at once, most common usage */
205 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
206 retval = VM_FAULT_OOM;
207 goto out_io_unlock;
208 }
209 }
210
211 /*
212 * Speculatively prefault a number of pages. Only error on
213 * first page.
214 */
215 for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
216 if (bo->mem.bus.is_iomem)
217 pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
218 else {
219 page = ttm->pages[page_offset];
220 if (unlikely(!page && i == 0)) {
221 retval = VM_FAULT_OOM;
222 goto out_io_unlock;
223 } else if (unlikely(!page)) {
224 break;
225 }
226 page->mapping = vma->vm_file->f_mapping;
227 page->index = drm_vma_node_start(&bo->vma_node) +
228 page_offset;
229 pfn = page_to_pfn(page);
230 }
231
232 if (vma->vm_flags & VM_MIXEDMAP)
233 ret = vm_insert_mixed(&cvma, address,
234 __pfn_to_pfn_t(pfn, PFN_DEV));
235 else
236 ret = vm_insert_pfn(&cvma, address, pfn);
237
238 /*
239 * Somebody beat us to this PTE or prefaulting to
240 * an already populated PTE, or prefaulting error.
241 */
242
243 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
244 break;
245 else if (unlikely(ret != 0)) {
246 retval =
247 (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
248 goto out_io_unlock;
249 }
250
251 address += PAGE_SIZE;
252 if (unlikely(++page_offset >= page_last))
253 break;
254 }
255out_io_unlock:
256 ttm_mem_io_unlock(man);
257out_unlock:
258 ttm_bo_unreserve(bo);
259 return retval;
260}
261
262static void ttm_bo_vm_open(struct vm_area_struct *vma)
263{
264 struct ttm_buffer_object *bo =
265 (struct ttm_buffer_object *)vma->vm_private_data;
266
267 WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
268
269 (void)ttm_bo_reference(bo);
270}
271
272static void ttm_bo_vm_close(struct vm_area_struct *vma)
273{
274 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
275
276 ttm_bo_unref(&bo);
277 vma->vm_private_data = NULL;
278}
279
280static const struct vm_operations_struct ttm_bo_vm_ops = {
281 .fault = ttm_bo_vm_fault,
282 .open = ttm_bo_vm_open,
283 .close = ttm_bo_vm_close
284};
285
286static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
287 unsigned long offset,
288 unsigned long pages)
289{
290 struct drm_vma_offset_node *node;
291 struct ttm_buffer_object *bo = NULL;
292
293 drm_vma_offset_lock_lookup(&bdev->vma_manager);
294
295 node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
296 if (likely(node)) {
297 bo = container_of(node, struct ttm_buffer_object, vma_node);
298 if (!kref_get_unless_zero(&bo->kref))
299 bo = NULL;
300 }
301
302 drm_vma_offset_unlock_lookup(&bdev->vma_manager);
303
304 if (!bo)
305 pr_err("Could not find buffer object to map\n");
306
307 return bo;
308}
309
310int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
311 struct ttm_bo_device *bdev)
312{
313 struct ttm_bo_driver *driver;
314 struct ttm_buffer_object *bo;
315 int ret;
316
317 bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
318 if (unlikely(!bo))
319 return -EINVAL;
320
321 driver = bo->bdev->driver;
322 if (unlikely(!driver->verify_access)) {
323 ret = -EPERM;
324 goto out_unref;
325 }
326 ret = driver->verify_access(bo, filp);
327 if (unlikely(ret != 0))
328 goto out_unref;
329
330 vma->vm_ops = &ttm_bo_vm_ops;
331
332 /*
333 * Note: We're transferring the bo reference to
334 * vma->vm_private_data here.
335 */
336
337 vma->vm_private_data = bo;
338
339 /*
340 * We'd like to use VM_PFNMAP on shared mappings, where
341 * (vma->vm_flags & VM_SHARED) != 0, for performance reasons,
342 * but for some reason VM_PFNMAP + x86 PAT + write-combine is very
343 * bad for performance. Until that has been sorted out, use
344 * VM_MIXEDMAP on all mappings. See freedesktop.org bug #75719
345 */
346 vma->vm_flags |= VM_MIXEDMAP;
347 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
348 return 0;
349out_unref:
350 ttm_bo_unref(&bo);
351 return ret;
352}
353EXPORT_SYMBOL(ttm_bo_mmap);
354
355int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
356{
357 if (vma->vm_pgoff != 0)
358 return -EACCES;
359
360 vma->vm_ops = &ttm_bo_vm_ops;
361 vma->vm_private_data = ttm_bo_reference(bo);
362 vma->vm_flags |= VM_MIXEDMAP;
363 vma->vm_flags |= VM_IO | VM_DONTEXPAND;
364 return 0;
365}
366EXPORT_SYMBOL(ttm_fbdev_mmap);
1/**************************************************************************
2 *
3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27/*
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29 */
30
31#define pr_fmt(fmt) "[TTM] " fmt
32
33#include <ttm/ttm_module.h>
34#include <ttm/ttm_bo_driver.h>
35#include <ttm/ttm_placement.h>
36#include <drm/drm_vma_manager.h>
37#include <linux/mm.h>
38#include <linux/rbtree.h>
39#include <linux/module.h>
40#include <linux/uaccess.h>
41
42#define TTM_BO_VM_NUM_PREFAULT 16
43
44static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
45 struct vm_area_struct *vma,
46 struct vm_fault *vmf)
47{
48 struct ttm_bo_device *bdev = bo->bdev;
49 int ret = 0;
50
51 spin_lock(&bdev->fence_lock);
52 if (likely(!test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)))
53 goto out_unlock;
54
55 /*
56 * Quick non-stalling check for idle.
57 */
58 ret = ttm_bo_wait(bo, false, false, true);
59 if (likely(ret == 0))
60 goto out_unlock;
61
62 /*
63 * If possible, avoid waiting for GPU with mmap_sem
64 * held.
65 */
66 if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
67 ret = VM_FAULT_RETRY;
68 if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
69 goto out_unlock;
70
71 up_read(&vma->vm_mm->mmap_sem);
72 (void) ttm_bo_wait(bo, false, true, false);
73 goto out_unlock;
74 }
75
76 /*
77 * Ordinary wait.
78 */
79 ret = ttm_bo_wait(bo, false, true, false);
80 if (unlikely(ret != 0))
81 ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
82 VM_FAULT_NOPAGE;
83
84out_unlock:
85 spin_unlock(&bdev->fence_lock);
86 return ret;
87}
88
89static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
90{
91 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
92 vma->vm_private_data;
93 struct ttm_bo_device *bdev = bo->bdev;
94 unsigned long page_offset;
95 unsigned long page_last;
96 unsigned long pfn;
97 struct ttm_tt *ttm = NULL;
98 struct page *page;
99 int ret;
100 int i;
101 unsigned long address = (unsigned long)vmf->virtual_address;
102 int retval = VM_FAULT_NOPAGE;
103 struct ttm_mem_type_manager *man =
104 &bdev->man[bo->mem.mem_type];
105 struct vm_area_struct cvma;
106
107 /*
108 * Work around locking order reversal in fault / nopfn
109 * between mmap_sem and bo_reserve: Perform a trylock operation
110 * for reserve, and if it fails, retry the fault after waiting
111 * for the buffer to become unreserved.
112 */
113 ret = ttm_bo_reserve(bo, true, true, false, NULL);
114 if (unlikely(ret != 0)) {
115 if (ret != -EBUSY)
116 return VM_FAULT_NOPAGE;
117
118 if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
119 if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
120 up_read(&vma->vm_mm->mmap_sem);
121 (void) ttm_bo_wait_unreserved(bo);
122 }
123
124 return VM_FAULT_RETRY;
125 }
126
127 /*
128 * If we'd want to change locking order to
129 * mmap_sem -> bo::reserve, we'd use a blocking reserve here
130 * instead of retrying the fault...
131 */
132 return VM_FAULT_NOPAGE;
133 }
134
135 /*
136 * Refuse to fault imported pages. This should be handled
137 * (if at all) by redirecting mmap to the exporter.
138 */
139 if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) {
140 retval = VM_FAULT_SIGBUS;
141 goto out_unlock;
142 }
143
144 if (bdev->driver->fault_reserve_notify) {
145 ret = bdev->driver->fault_reserve_notify(bo);
146 switch (ret) {
147 case 0:
148 break;
149 case -EBUSY:
150 case -ERESTARTSYS:
151 retval = VM_FAULT_NOPAGE;
152 goto out_unlock;
153 default:
154 retval = VM_FAULT_SIGBUS;
155 goto out_unlock;
156 }
157 }
158
159 /*
160 * Wait for buffer data in transit, due to a pipelined
161 * move.
162 */
163 ret = ttm_bo_vm_fault_idle(bo, vma, vmf);
164 if (unlikely(ret != 0)) {
165 retval = ret;
166 goto out_unlock;
167 }
168
169 ret = ttm_mem_io_lock(man, true);
170 if (unlikely(ret != 0)) {
171 retval = VM_FAULT_NOPAGE;
172 goto out_unlock;
173 }
174 ret = ttm_mem_io_reserve_vm(bo);
175 if (unlikely(ret != 0)) {
176 retval = VM_FAULT_SIGBUS;
177 goto out_io_unlock;
178 }
179
180 page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
181 vma->vm_pgoff - drm_vma_node_start(&bo->vma_node);
182 page_last = vma_pages(vma) + vma->vm_pgoff -
183 drm_vma_node_start(&bo->vma_node);
184
185 if (unlikely(page_offset >= bo->num_pages)) {
186 retval = VM_FAULT_SIGBUS;
187 goto out_io_unlock;
188 }
189
190 /*
191 * Make a local vma copy to modify the page_prot member
192 * and vm_flags if necessary. The vma parameter is protected
193 * by mmap_sem in write mode.
194 */
195 cvma = *vma;
196 cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);
197
198 if (bo->mem.bus.is_iomem) {
199 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
200 cvma.vm_page_prot);
201 } else {
202 ttm = bo->ttm;
203 if (!(bo->mem.placement & TTM_PL_FLAG_CACHED))
204 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
205 cvma.vm_page_prot);
206
207 /* Allocate all page at once, most common usage */
208 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
209 retval = VM_FAULT_OOM;
210 goto out_io_unlock;
211 }
212 }
213
214 /*
215 * Speculatively prefault a number of pages. Only error on
216 * first page.
217 */
218 for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
219 if (bo->mem.bus.is_iomem)
220 pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
221 else {
222 page = ttm->pages[page_offset];
223 if (unlikely(!page && i == 0)) {
224 retval = VM_FAULT_OOM;
225 goto out_io_unlock;
226 } else if (unlikely(!page)) {
227 break;
228 }
229 page->mapping = vma->vm_file->f_mapping;
230 page->index = drm_vma_node_start(&bo->vma_node) +
231 page_offset;
232 pfn = page_to_pfn(page);
233 }
234
235 if (vma->vm_flags & VM_MIXEDMAP)
236 ret = vm_insert_mixed(&cvma, address, pfn);
237 else
238 ret = vm_insert_pfn(&cvma, address, pfn);
239
240 /*
241 * Somebody beat us to this PTE or prefaulting to
242 * an already populated PTE, or prefaulting error.
243 */
244
245 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
246 break;
247 else if (unlikely(ret != 0)) {
248 retval =
249 (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
250 goto out_io_unlock;
251 }
252
253 address += PAGE_SIZE;
254 if (unlikely(++page_offset >= page_last))
255 break;
256 }
257out_io_unlock:
258 ttm_mem_io_unlock(man);
259out_unlock:
260 ttm_bo_unreserve(bo);
261 return retval;
262}
263
264static void ttm_bo_vm_open(struct vm_area_struct *vma)
265{
266 struct ttm_buffer_object *bo =
267 (struct ttm_buffer_object *)vma->vm_private_data;
268
269 WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
270
271 (void)ttm_bo_reference(bo);
272}
273
274static void ttm_bo_vm_close(struct vm_area_struct *vma)
275{
276 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
277
278 ttm_bo_unref(&bo);
279 vma->vm_private_data = NULL;
280}
281
282static const struct vm_operations_struct ttm_bo_vm_ops = {
283 .fault = ttm_bo_vm_fault,
284 .open = ttm_bo_vm_open,
285 .close = ttm_bo_vm_close
286};
287
288static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
289 unsigned long offset,
290 unsigned long pages)
291{
292 struct drm_vma_offset_node *node;
293 struct ttm_buffer_object *bo = NULL;
294
295 drm_vma_offset_lock_lookup(&bdev->vma_manager);
296
297 node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
298 if (likely(node)) {
299 bo = container_of(node, struct ttm_buffer_object, vma_node);
300 if (!kref_get_unless_zero(&bo->kref))
301 bo = NULL;
302 }
303
304 drm_vma_offset_unlock_lookup(&bdev->vma_manager);
305
306 if (!bo)
307 pr_err("Could not find buffer object to map\n");
308
309 return bo;
310}
311
312int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
313 struct ttm_bo_device *bdev)
314{
315 struct ttm_bo_driver *driver;
316 struct ttm_buffer_object *bo;
317 int ret;
318
319 bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
320 if (unlikely(!bo))
321 return -EINVAL;
322
323 driver = bo->bdev->driver;
324 if (unlikely(!driver->verify_access)) {
325 ret = -EPERM;
326 goto out_unref;
327 }
328 ret = driver->verify_access(bo, filp);
329 if (unlikely(ret != 0))
330 goto out_unref;
331
332 vma->vm_ops = &ttm_bo_vm_ops;
333
334 /*
335 * Note: We're transferring the bo reference to
336 * vma->vm_private_data here.
337 */
338
339 vma->vm_private_data = bo;
340
341 /*
342 * We'd like to use VM_PFNMAP on shared mappings, where
343 * (vma->vm_flags & VM_SHARED) != 0, for performance reasons,
344 * but for some reason VM_PFNMAP + x86 PAT + write-combine is very
345 * bad for performance. Until that has been sorted out, use
346 * VM_MIXEDMAP on all mappings. See freedesktop.org bug #75719
347 */
348 vma->vm_flags |= VM_MIXEDMAP;
349 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
350 return 0;
351out_unref:
352 ttm_bo_unref(&bo);
353 return ret;
354}
355EXPORT_SYMBOL(ttm_bo_mmap);
356
357int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
358{
359 if (vma->vm_pgoff != 0)
360 return -EACCES;
361
362 vma->vm_ops = &ttm_bo_vm_ops;
363 vma->vm_private_data = ttm_bo_reference(bo);
364 vma->vm_flags |= VM_MIXEDMAP;
365 vma->vm_flags |= VM_IO | VM_DONTEXPAND;
366 return 0;
367}
368EXPORT_SYMBOL(ttm_fbdev_mmap);